Against

Hype surrounds no device like the iPhone. Love it or loathe it, you certainly can't deny the impact that Apple and the iPhone has had on mobile phones as we know them. The arrival of the iPhone 4S ushers in only the fifth mobile phone that Apple has sold since if first launched the iPhone in 2007. Compare that to HTC, which has launched more than five devices in the last 6 months, and you start to see how much stock each iPhone device holds.

With pre-orders and sales breaking records for a device that hasn't fundamentally changed that much over the last iteration, is the iPhone still breaking new ground in the world of smartphones, or is it now playing catch up?

Design and build

The iPhone 4S is basically the same design as the iPhone 4. The lack of exterior redesign follows the trend that Apple set with the iPhone 3G and iPhone 3GS, the devices look the same, except for a few minor exterior tweaks to accommodate the new dual antenna inside.

This change amounts to a slight move of the mute switch, so it is closer to the volume up button than before. For this reason alone, your existing iPhone 4 case may not fit.

Otherwise, the iPhone 4S is a sandwich of glass and metal. It's precisely designed, like all Apple products and whilst we think the iPhone 4S is a beautiful looking mobile phone, there's no denying the edges are sharp and it isn't the most comfortable for making long calls on if you are holding it up to your ear. Not that that small detail would prevent you from buying one.

Black and white versions of the phone are now available at launch, avoiding the somewhat farcical situation with white iPhone 4 handsets in the past.

The build quality is excellent. The iPhone 4S feels solid in the hand, there are no creaks, the buttons are positive and precise in their actions and it feels like a phone that will stand the test of time - assuming you don't drop it. For many, the iPhone 4S is destined to hide within a case or cover, which we think is a real shame as it's a great phone to look at naked.

The display remains at 3.5 inches, giving you the same resolution of 960 x 640, and at 326ppi remains one of the sharpest displays around. Viewing angles are excellent and colour rendition very good, although we've found it looks a little warmer than the iPhone 4 display. Independently, you probably won't notice that the whites are slightly more yellow, but together, we've found that some prefer the brighter whites of the iPhone 4, some prefer the vibrancy of the iPhone 4S.

If you've only ever used the iPhone, then the screen size will suit. But if you've been tinkering with a 4- or 4.3-inch display, you might find things are a little small. Windows Phone 7 and Android will have another year of lording it over iPhone users, but you don't miss out on functionality because you have a small screen and that's the important point.

What's inside?

One of the main upgrades to this iPhone is the new A5 processor. This has been languishing in the iPad 2 for the past 6 months, so it is no surprise to see it jump to the iPhone 4S. It offers you a 1GHz dual-core processor, so at the very least it brings you up to speed with rival devices on other platforms, whilst also offering the sort of power you'll find in Apple's other "mobile" device.

As both the iPad and the iPhone share the same operating system in iOS 5, this makes perfect sense. Apple isn't playing the numbers game in quite the same way that Android manufacturers are, but the RAM is estimated at around 600MB.

To be honest, the actual technical specification of the hardware that drives the iPhone 4S is almost irrelevant: it is more powerful than the last generation, pushing forward new capabilities for the effective 12-months that the phone will be the darling of Apple's line-up. Not having a 1.5GHz processor or 1GB of RAM doesn't matter so long as iOS 5 runs smoothly, the apps work well and the user experience is maintained. In that respect, a direct comparison with rival platforms, on a numbers basis, is meaningless.

Setting the iPhone 4S alongside the iPhone 4, both configured identically - which, thanks to iCloud restore, is incredibly easy - and it becomes apparent just how much of a performance increase the iPhone 4S offers you. Apps open much faster than before, but it isn't until you get the two devices side-by-side that you'll really notice, as the iPhone 4 was no slouch.

Where this puts the iPhone 4S in terms of future apps, games and opportunities remains to be seen, but part of that performance upgrade helps run the new camera on the rear of the phone.

Cameras

Where Apple does seem to be playing the numbers game, is on the camera. Cramming 8-megapixels into the iPhone 4S might make it seem competitive, but we have to wonder whether this is any better than a 5-megapixel unit. There is more data to deal with, certainly, and this is something that a new processor and GPU will have to cope with, but essentially the real difference lies in the BSI aspect, or backside illumination.

This really means that the imaging sensor has a different design to previous units. It handles light better, it's less prone to noise and is more efficient. It also happens to be the same number of megapixels as top-tier Android rivals.

Comparing the iPhone 4 and the iPhone 4S images side-by-side, it’s immediately obvious that the iPhone 4S camera is considerably better. There is less noise in shots and colours are better rendered. Overall levels of detail are much improved too and, down at a pixel level, things are impressively sharp.

Of course, in lower lighting conditions noise quickly comes crashing in and the flash on the back can do little to help you along. In good conditions though, you'll get some cracking shots out of it.

One of the notable features of the camera is that you get no settings. You can toggle the rule of thirds grid, you can engage the HDR mode, but that is it. You can't change the resolution of image capture, you can't tweak the saturation or exposure and you don’t get any built-in effects. You do get touch focusing however, so you can easily and deliberately focus where you want, with the added benefit of using the volume up button as the shutter if you want. And you can now pinch to zoom, but that's about it.

The same lack of effects applies to the video capture too. You now get Full HD 1920 x 1080 pixels at 30fps. The results are surprisingly good, but you don't get any options to turn this down to a lesser resolution. As a result it will begin eat a fair amount of space – a 30 second clip is about 100MB – if you shoot a lot of video.

Again you get touch focusing, but the iPhone 4S doesn't offer you continuous autofocus during video capture. You can refocus whilst filming by touching a new focal point on the screen, but it can pulse a little whilst trying to achieve sharp focus. Some rivals offer smoother transitions, so you can move the camera from a close macro subject to something in the distance whilst keeping the whole things sharp, which the iPhone fails to achieve.

In terms of quality, it's up there with the best phones we've seen, but the option for continuous autofocus during filming would be top of our list of changes.

iOS 5 features

iOS 5 brings with it a number of updates to an iPhone that remains, visually, very much the same as the previous iteration of devices. The interface is largely unchanged: you get each app laid out on the ever-expanding pages. You can order them into folders if you wish, but there's nothing new here.

iOS 5's changes mostly lie under the skin, a subtle tweak here and there, giving you more options, new integrated services and the ushering in of some new apps. We've had a good detailed look at iOS 5 in a separate review; what we'll deal with here is the significant changes that the new OS brings, and those aspects that are unique to the iPhone 4S.

One of the changes we appreciate the most is a redesign of the notifications. Each type can be customised, so rather than a universal alert that dominates the entire screen, you can opt for banners instead if that suits you better. You can control how you see your alerts on the lockscreen with the ability to unlock straight to a particular message.

You also get a drag down notifications tray, much like Android offers. This groups alerts, as well as offering weather and stocks widgets, so you can easily see notifications you might need to action. In short, Apple's notifications has taken something that Android did well and surpassed it. It was a long time coming, but is much better for it.

Many of the iOS 5 alterations address larger trends in smartphones. The introduction of iCloud and Wi-Fi syncing with iTunes cuts the computer tie that the iPhone had until recently. Again, this addresses something that Android holds over Apple: Android's core systems leverage native cloud assets very well. Calendars, contacts and emails now potentially have a cloud element on iOS 5, as well as a backup infrastructure.

In truth, backing-up your entire device, settings, apps and all to iCloud is rather neat and something that Android can't tackle so easily given the number of different devices the OS runs on. Apple, on the other hand, can backup your iPhone to iCloud and restore it to a replacement device, in very little time, and without issue.

Wi-Fi syncing has raised an issue for some, as we've heard that some PC users find that iTunes launches in Windows every time their iPhone comes into range. We've not had this problem on the Mac. iTunes, although not mandatory any more, does feel like the weak link in the iPhone package: it's slow to navigate at times and managing your device through iTunes can sometimes feel like a real chore.

You now get a new messaging service called iMessage. It is very much the text companion of FaceTime, and like Apple's video service, operates from iDevice to iDevice. As such, you'll need to know the Apple ID of the person you want to iMessage, at which point your message will change from using the mobile phone network to the data network. That advantage this offers is you can essentially message for free when connected to Wi-Fi.

Finding a person's Apple ID isn't as hard as it sounds – if you pick the right contact, the message window will change from SMS messaging to iMessage and you'll see the difference. The downside is that if your person moves from device to device, or has multiple Apple devices on the same account, messages will arrive at all points. A message can be delivered to an iPad whilst the owner is walking around with their BlackBerry and they'd never know, so iMessage isn't suitable for really important things at all.

You can turn off iMessage to avoid this, as well as being able to manage which numbers or email addresses it will work with, so with some fiddling, you should be able to get it working the right way for you and your network of contacts.

One of the trump cards that the iPhone 4S can flourish is that it is stable. Other platforms struggle to be as fast and reliable as iOS. It isn't free from problems and you get the occasional hiccup, but they are rare. Slowdown isn't a problem, apps are fast to open, with the new processor really speeding things up. It's quick to deliver on data applications too. Anyone who has used the Android Facebook app will know how slow it can be: under iOS those connected services are delivered in a flash.

Time to talk Siriously

With little physical change to the iPhone 4S, much of the excitement has been dedicated to Siri, Apple's voice-activated personal assistant. Siri was a service that Apple purchased and has integrated with core applications of the iPhone 4S. Like Google's voice searching, it relies on a data connection to interpret what you've said.

Siri is something of a hybrid application, offering a degree of hands-free autonomy. At some times it returns responses on the display, like your calendar appointments, or a contact's address, at other times it gives you complete voice control.

You can, for example, fire up a text message, dictate that message, address it and send it with touching the screen once. This is where Siri excels, as is the straightforward convenience of being able to ask questions to find the time in a different place, set yourself reminders and so on.

A fair amount of criticism has been levelled at Apple because not all of Siri's functions are available outside of the US at present (they're expected to hit around the world in 2012). But, this isn't a huge problem because you can leverage the Safari browser to find local and business information in much the same way, thanks to Google. It lacks the Apple polish, but it gets the job done which is the important point.

Learning to use Siri to the best effect is the most important thing. It might not be the main reason to buy the iPhone 4S and we can't see any enduring novelty value in asking it stupid questions. Once you get it working for you well, it can quickly become part of your normal phone interaction - especially as you can use it when wearing a headset with the in-line Apple remote, making it much more accessible out in public.

The final word on Siri has to be that the interpretation of what you say is the clever part in this and from this foundation it could be much more useful, so we suspect that in the future, Siri will be of even greater benefit.

Twitter, browser and apps

Twitter is now integrated as a sharing option, making it really easy to get those websites, photos and general comments out to the world. Although the Twitter app will do all this for you, it's the inclusion in the options menu that brings it to the fore.

No other service or social network gets this privilege: if you want to Facebook, you need the Facebook app. If you want to post something on Flickr, you need to do it via an app. This is in stark contrast to Android, which will let pretty much any app get included in your sharing options. The iPhone 4S stays nice and tidy because it is limited, but we'd love to have the choice to change it just slightly to better suit us.

The browsing experience is nice and fast, with the high-resolution display meaning that you can resolve fine text. Of course Flash is one of the things you don't get. You can't just run to any site online and watch the video treats like you can on Android. However, with the iPhone forming such as large customer base, in many cases moves have been made to accommodate this deficiency. Android is great because you can watch catch-up TV on the 4OD website: iOS is great because it gets its own app.

Battery and calling

Finally, we come to battery life, which, on the 4S has raised some concerns if the response on forums is anything to go by. During testing we've been running both an iPhone 4 and an iPhone 4S set-up identically.

In one test, we took both phones on a day trip to Berlin. The iPhone 4S didn't have roaming enabled on the account, so was effectively in standby for the duration of the trip. It still managed to get through its battery as fast as the phone that was still connected, taking calls and sucking data.

However, make a few tweaks and things settle down a lot. The biggest concern was the way the iPhone 4S used battery when in standby. This seemed to be down to Siri's “Raise to Speak” feature, and disabling that improved things greatly. Those new live widgets for weather and stocks also seemed to make a difference so we found ourselves switching them off too.

Some will argue that you should be able to run a phone with all the features enabled and get it through the day. The iPhone 4S won't do that, so you have to be more objective about managing the phone - in the same fashion that Android users have become accustomed too.

We're sure that Apple will be able to improve the situation with software management solutions, after all, they only have one phone to deal with, rather than a huge range like Android manufacturers do.

With power saving measures, our iPhone 4S battery performance is only slightly less than the iPhone 4 we have on iOS 5, getting us through most of the day in average use. It you dock at home and dock at work, it will be fine.

When it comes to calling, and that new antenna, we have found that reception has been great. Callers come across loud and clear, and we like the fact that iOS is clever enough to recognise shared numbers in your phone, so it will say "Mum or Dad calling" rather than the first person alphabetically.

But we do wish that call rejection options were offered on the screen. For the lockscreen you only get “swipe to answer” and we wish there was an opposing swipe to cancel, rather than fishing around to press a button.

Verdict

The iPhone 4S is every bit a smartphone, and an excellent one at that. The range of functionality that it delivers, along with the entire ecosystem that it inhabits, still make it one of the best phones on the market. Apple has done an excellent job pushing things like the App Store and incorporating features that see wider adoption, like AirPlay, its wireless streaming system, for example.

Although we're not huge fans of iTunes as a software package, there is some convenience in having an end-to-end system that will deliver your music and movies in a format you can enjoy simply any easily. The headphones in the box are still poor, but you're spoilt for choice when it comes to buying accessories.

It's easy to criticise the iPhone for the things it doesn't have: the screen could be bigger, the battery life should be longer, iOS still could be improved, there is no NFC, Flash support or options for memory expansion. But you have to decide whether these things are important to you. If they are, you now have many choices elsewhere.

To us, the iPhone 4S feels as though it has responded to the competition, it's adapted a better notifications system, and ushered in new features, but in many ways we can't help feeling it has adopted some of the nice things about Android. For some, the concern might be that it's adapted Android's battery management issue too. The iPhone 4S is likely to be exactly what some people are looking for. For others, the excitement in other smartphone quarters could well draw their eye.

Chris sits in the Editor’s chair, guiding the good ship Pocket-lint through the tumultuous seas of an ever-changing world of tech. Involved with Pocket-lint from its foundation, he’s best known for his critical eye and throwaway snark.